are we all trading different versions of the same chart?

when looking at longer timeframes, are we all trading different versions of the same chart? for example, if EURUSD shoots up, USDXXX pairs shoot down and EURXXX pairs shoot up. this is one thing that puts me off opening multiple orders -- the way i see it is that trading these "multiple" trends is the same as trading one big trend.

If the EUR goes up it means someone, somewhere, is selling USD (EURUSD goes up). Therefore if there is a general sense in the market that the Dollar is weak the USD pairs will go down.

If you trade two pairs, say EURUSD and GBPUSD, and the Dollar strengthens for some reason then you end up losing twice.

I only trade on pair at a time, generally EURUSD, and forget the rest and base all my trading judgements on the one chart. It keeps life simple.

Currency pairs with the one same currency don't have correlation equal to 1. They are correlated but sometimes you can see GBP/USD going down when EUR/USD is rising or USD/JPY up when GBP/JPY is down.

And there are pairs that aren't correlated at all - like CHF/JPY and EUR/GBP.